BURBANK — The Bob Hope Airport is quieter today than it was before a new generation of aircraft began operating there, but there are still 10 private jets based at the airport that can sometimes bend the eardrum. Since 1987, the airport has required all commercial airlines flying in and out of the airport to be Stage 3 aircraft, a type of plane that is built to be less noisy. But bans on the noisier Stage 2 aircraft do not apply to general aviation flights.

As a result, private jets used for transporting executives can be louder than those from a commercial airline, said Victor Gill, a spokesman for the airport. Stage 2 aircraft make more of a thunderous noise than Stage 3 planes, which generally register as more of a whistling sound.

“Typically a person who is bothered by that type of a noise will complain about phone conversation interruption, or TV or music interruption,” Gill said.

Thirty-one general aviation planes based at the Bob Hope Airport are Stage 3 aircraft, while 10 of them are in the Stage 2 category, Gill said. In the 12 months between June 2003 through May 2004, there were 1,768 takeoffs and landings of Stage 2 aircraft at the airport.

The airport has a voluntary 10 p.m. to 7 a.m. curfew on airline flights. Cargo planes are for the most part abiding by the voluntary curfew, but Federal Express has a flight that comes in at 5 a.m., Gill said.

And Ameriflight, a courier company based at the Bob Hope Airport, has about 20 to 25 flights that operate throughout the night, he said. The company has several Stage 3 jets and propeller planes.

Stage 2 planes are an issue the Burbank city officials are discussing with the airport authority, said Peter Kirsch, special counsel to the city on airport issues.

“The greatest noise concern at the airport is nighttime flights. The second greatest concern is Stage 2 aircraft, night or day,” Kirsch said.

“The gross amount of noise at this airport is substantially less than it was 10 or 15 years ago; it still doesn’t mean that people find it acceptable,” he said.

The noise from a Stage 2 aircraft can be up to four times as loud to the human ear as that from the newer versions, he said.

Under a proposed agreement between the city and the airport, the two sides would work cooperatively on reducing nighttime noise at the airport. The agreement, which could be approved in November, would also keep the airport from building a new terminal for 10 years.

The airport allows certain models of Stage 2 Gulfstream jets to fly at night if they are below a specified weight, Gill said.

Howard Rothenbach, the head of Restore Our Airport Rights, said his chief concern is that the number of flights at the airport will increase, but he added that Stage 2 aircraft are also a concern.

“Some of those pilots, I don’t know if they’re in a hurry or what, but they come screaming off the end of the runway,” Rothenbach said.

“If they were more respectful, it isn’t quite as bad because they throttle off” and make less noise, he said.